DS18B20驱动

只看该作者 · 2009-12-2 16:31

修改人家的,原来是用systick做的延时,我用的3.12的库,发现不能用
于是我改成tim2来延时
#ifndef _DS18B20_H_
#define _DS18B20_H_

#include "stm32f10x.h"

#ifndef _DS18B20_LOCAL
#define DS18B20_EXTERN extern
#else
#define DS18B20_EXTERN
#endif

#define DS18B20_BIT       GPIO_Pin_9
#define DS18B20_PORT       GPIOC

#define READ_DS18B20()       GPIO_ReadInputDataBit(GPIOC, DS18B20_BIT)

#define DIR_1WIRE_IN()       {DS18B20_PORT->CRH &= 0xFFFFFF0F;GPIOC->CRH |= 0x00000040;}
#define DIR_1WIRE_OUT()       {DS18B20_PORT->CRH &= 0xFFFFFF0F;GPIOC->CRH |= 0x00000030;}
#define CLR_OP_1WIRE()       GPIO_ResetBits(DS18B20_PORT, DS18B20_BIT)
#define SET_OP_1WIRE()       GPIO_SetBits(DS18B20_PORT, DS18B20_BIT)
#define CHECK_IP_1WIRE() GPIO_ReadInputDataBit(DS18B20_PORT, DS18B20_BIT)

DS18B20_EXTERN void DS18B20_init(void);
DS18B20_EXTERN void DS18B20_Convert(void);
DS18B20_EXTERN u16  DS18B20_Read(void);
DS18B20_EXTERN void delay_nus(vu32 nCount);

#endif

只看该作者 · 2009-12-2 16:32

#define _DS18B20_LOCAL
#include "ds18b20.h"
#include "stm32f10x.h"
#include "stm32f10x_conf.h"
//把下面这段复制到主程序
/**************************************************************************/
//  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
//  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
//  TIM_TimeBaseStructure.TIM_Period = 1;                //自动装载
//  TIM_TimeBaseStructure.TIM_Prescaler = 72;    //72M分频率到1MHz
//  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
//  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Down;  //向下计数
//  TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/**************************************************************************/
void delay_nus(vu32 nCount)
{
  u16 TIMCounter = nCount;
  TIM_Cmd(TIM2, ENABLE);
  TIM_SetCounter(TIM2, TIMCounter);
  while (TIMCounter)
  {
TIMCounter = TIM_GetCounter(TIM2);
  }
  TIM_Cmd(TIM2, DISABLE);
}

/*******************************************************************************
*******************************************************************************/

void DS18B20_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

// PC9-DQ
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(DS18B20_PORT, &GPIO_InitStructure);
}

//单总线上的所有处理均从初始化开始
void init_1820()
{
DIR_1WIRE_OUT();
SET_OP_1WIRE();
CLR_OP_1WIRE();
delay_nus(500); //480us以上
SET_OP_1WIRE();
DIR_1WIRE_IN();
delay_nus(30);    //15~60us
while(CHECK_IP_1WIRE());
DIR_1WIRE_OUT();
SET_OP_1WIRE();
delay_nus(100); //60~240us
}
/*
指令                   代码
Read ROM(读ROM)       [33H]
Match ROM(匹配ROM)    [55H]
Skip ROM(跳过ROM]    [CCH]
Search ROM(搜索ROM)    [F0H]
Alarm search(告警搜索)  [ECH]

指令代码
Write Scratchpad(写暂存存储器) [4EH]
Read Scratchpad(读暂存存储器) [BEH]
Copy Scratchpad(复制暂存存储器) [48H]
Convert Temperature(温度变换) [44H]
Recall EPROM(重新调出) [B8H]
Read Power supply(读电源) [B4H]
*/
void write_1820(u8 x)
{
u16 i;

for(i=0; i<8; i++)
{
   CLR_OP_1WIRE();
   if(x & 0x01) //写数据了，先写低位的！
   SET_OP_1WIRE();
   else
   CLR_OP_1WIRE();
x>>=1;
   delay_nus(30); //15~60us
   SET_OP_1WIRE();
}
SET_OP_1WIRE();
}
u8 read_1820(void)
{
u16 i;
u8 x = 0;

DIR_1WIRE_OUT();
for(i=0; i<8; i++)
{
      CLR_OP_1WIRE();
      x >>= 1;
SET_OP_1WIRE();
      DIR_1WIRE_IN();
      //读数据,从低位开始
      if(CHECK_IP_1WIRE())
        x |= 0x80;
      delay_nus(100); //60~120us
      DIR_1WIRE_OUT();
}
return (x);
}

/*
返回值是温度
格式s,s,s,s, s,b6,b5,b4, b3,b2,b1,b0, b-1,b-2,b-3,b-4
转换为十进制
温度 T = (int)val*10/16;
放大了10倍，个位是小数部分。

*/
void DS18B20_Convert(void)             //温度转换
{
   init_1820();       //复位18b20
   write_1820(0xcc); // 发出转换命令
   write_1820(0x44);
}

u16 DS18B20_Read(void)                //读取温度值
{
u16 res;
init_1820();
write_1820(0xcc);  //发出读命令
write_1820(0xbe);
res=read_1820();  //读数据
res+=(u16)read_1820()<<8;
return res;
}

只看该作者 · 2012-3-22 22:03

谢谢楼主，我刚好要做个这个，先试试看。

DS18B20驱动

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